Collagen is not a single molecule ; there are 28 distinct types . The most abundant are types I , II and III . Type I collagen is found in tendons , ligaments , corneas , bones and skin . Type III collagen is typically found alongside type I collagen in the skin and blood vessels . Type II collagen is mostly found in cartilage .
Hydrolysed collagen is the most common form in the supplement market . When native collagen is heated , it denatures to form gelatin . However , gelatin has low solubility , so hydrolysing collagen creates shorter amino acid chains , increasing their solubility and absorption rate .
Collagen metabolism
When collagen is eaten , it is digested and absorbed into the bloodstream , where both single amino acids and unique dipeptides and tripeptides appear . These small peptides have a unique fingerprint because of the presence of the amino acid hydroxyproline . Remember , hydroxyproline is unique to collagen so these small peptide fragments only exist in the blood from collagen breakdown or from the collagen we eat .
Absorbed collagen peptides not only redistribute to the skin but can act as signalling molecules , binding to receptors on the surface of fibroblasts . Fibroblasts are skin cells that are major producers of collagen . This receptor binding stimulates fibroblasts to produce collagen , elastin ( needed for skin elasticity ) and hyaluronic acid ( for water retention ). This is a key point as it provides a plausible mechanism by which collagen consumption could directly affect our skin .
Collagen supplements and skin health
Collagen degradation begins in our 20s and is accelerated by sun exposure , smoking , environmental pollution , alcohol abuse and nutrient deficiencies . This results in skin volume reduction , loss of elasticity , decreased skin epidermal thickness , wrinkles and reduced moisture retention capacity - the typical visual signs of ageing .
So , can collagen supplements promote healthy skin ? Over 25 randomised-controlled trials have investigated this question , and the answer is remarkably consistent : yes . A systematic review published in the International Journal of Dermatology in 2021 looked at 19 of these trials . In all studies , the participants and researchers assessing the effects were blinded to whether a person was taking collagen or a placebo .
The results of this review were significant . Supplementation with hydrolysed collagen had a statistically significant effect on skin hydration , elasticity , density and wrinkles . Many of
THERE IS GOOD EVIDENCE THAT HYDROLYSED COLLAGEN IMPROVES VARIOUS ASPECTS OF SKIN HEALTH IN AGEING , WITH GROWING EVIDENCE FOR ITS USE IN OSTEOARTHRITIS , SPORTS INJURIES AND EXERCISE RECOVERY . these clinical trials were independently funded , with no commercial conflict of interest from the authors . Effective collagen doses used in the trials ranged from 0.6 g to 12 g per day for 1 to 3 months . And not a single study reported an adverse health problem from taking collagen .
Other benefits of collagen
Collagen research isn ’ t just about skin health . Several clinical trials have examined collagen ’ s effects on osteoarthritis , with the research indicating a clinically significant reduction in joint stiffness , pain and function .
Collagen makes up about threequarters of the dry weight of tendons - making its use a popular choice by athletes for injury and exercise recovery . The small number of clinical trials in this area so far suggests a benefit in soft tissue repair and improving exercise-related joint pain and joint functionality .
There is also some interesting preliminary research showing that hydrolysed collagen may improve lipid metabolism , insulin sensitivity and hypertension in people with type 2 diabetes . So , keep an eye on this space as the research progresses .
The bottom line
Most of the criticisms about collagen supplements in the popular press are largely unfounded and do not reflect the scientific evidence . There is good evidence that hydrolysed collagen improves various aspects of skin health in ageing , with growing evidence for its use in osteoarthritis , sports injuries and exercise recovery . All this from something that is naturally part of foods and has little evidence of any adverse health problems .
YMCA HEALTHY LIVING MAGAZINE 9